Method and system for automatic handling of optical assemblies

ABSTRACT

Systems and methods are used for automatic handling of optical fibers and transporting the same, as well as automatic assembly of the optical fibers into optical devices and transportation of the same. A spool facilitates handling, storing, and transporting of the optical fiber. A cassette receives an electronic module and the optical fiber, with or without a corresponding spool, and presents the fiber in a manner that facilitates automatic assembly of optical assemblies. The cassette also facilitates handling, storing, and transporting of the optical assemblies.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional ApplicationSerial No. 60/270,980 entitled “Fiber Cassette” and U.S. ProvisionalApplication Serial No. 60/270,979 entitled “Optical Fiber Spool andCassette”, both filed Feb. 23, 2001.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to systems and methods forautomatic handling of optical fibers, transporting the fibers, andautomatically assembling the optical fibers into optical devices,including attaching the fibers to electro-optical modules. The presentinvention also relates to automatic handling of optical assemblies andtheir transportation.

[0004] 2. Description of the Background

[0005] In the production of optical systems including electro-opticalsystems, certain components must be optically connected to othercomponents. This optical connection is typically accomplished by usingflexible optical fibers with connectors on their ends. The use of aconnector in such systems, however, generates a degradation of thesignal either in a reduction of power or in added distortion. This isreferred to as insertion loss. In many optical devices, therefore, oneend of the fiber is connected directly to an electronic unit in order toeliminate one connector and reduce the system's insertion loss. This isnormally done by the use of flexible optical fibers such as pigtails.Pigtails are glass fibers with specified coatings and have connectorsinstalled on one end. They are normally obtained in lengths from a fewinches to several feet. These fibers can be obtained with many differentend terminations and are typically very fragile. Most of these fibers,for instance, cannot be bent in a curve with a radius that is less than1.5 inches without suffering significant damage. The weight of typicalend terminations on most pigtails presents a substantial risk of fiberdamage during transportation and assembly. Also, the bare ends of fibersthat are subject to direct connection are very fragile and must beprotected from contact with any external surface at all times.

[0006] In order to assemble electro-optical systems, optical fibers areinitially shipped from a fiber manufacturer. In connection with theshipping process, optical fibers undergo multiple manual processes.Optical fibers are normally air coiled, placed individually in plasticbags, and shipped from a vendor to a module manufacturer. There, theindividual optical fiber is again subjected to numerous manualprocesses. The fiber packaging is opened manually. The optical fibersare uncoiled manually. The optical fibers are placed into equipment formanual assembly. These manual processes, particularly the shippingprocess and the assembly process, present a strong risk of damage tooptical fibers. The fragile nature of pigtails, in particular, requiresoperator dexterity and does not lend itself to handling equipmentnormally used in automated assembly.

[0007] Once incorporated into an electro-optical assembly, in which afiber is attached to an electronic module, the fiber is handled andshipped again. Once the fiber has been attached to an electronic module,however, its exposure to a substantial risk of damage increases.Handling the device, while these delicate fibers are hanging freely, andmaking connections to the attached fiber numerous times for fiberalignment and unit testing, generates a high probability of fiberfracture. Thus, the shipping of the finished device, with its attachedfibers, typically requires manual manipulation of the fibers in properlysized loops and some method of immobilizing the fibers with respect tothe body of the module. The device and the attached optical fibers mustbe placed in properly designed packing material. Fiber motion duringshipment to the end user can generate defective units that may appear tobe of high quality, but will not function properly in service.

[0008] In order to minimize the above-referenced risks, extreme care inhandling during shipping and assembling is required. Nevertheless, smallfractures can occur in the optical fibers that may not reveal themselvesuntil the fracture grows sufficiently large to degrade the passage oflight. This results in a reduction in the lifetime of theelectro-optical assembly with the necessity of early unit replacementand resultant cost implications. Thus, there exists a need for a systemand method for handling, transporting, and assembling optical fibers andoptical assemblies, including electro-optical assemblies, that overcomethe problems present in the prior art.

BRIEF SUMMARY OF THE INVENTION

[0009] The present invention is directed to a spool assembly to be usedin connection with automatic assembly equipment, which captures a lengthof optical fiber having a first end and a second end. The spool includesa drum for receiving the optical fiber. The spool also includes a spoolbase, coupled to the drum, which includes at least two fiber end areasfor retaining the first and second ends. The present invention is alsodirected to a spool assembly to be used in connection with automaticassembly equipment, which captures a length of optical having a firstend and a second end. The spool includes a drum for receiving the lengthof optical fiber and a spool base, coupled to the drum. The spool baseincludes a fiber connector area, for retaining the first end andpresenting the first end for connection to a light source or lightsensor, and a module connection area, for retaining the second end andpresenting the second end for automatic connection to an electronicmodule.

[0010] The present invention is also directed to cassette thatfacilitates automatic assembly of an electro-optical device thatincludes at least one length of optical fiber (having a first end and asecond end) and an electronic module. The cassette includes anelectronic module receiving area that receives the electronic module anda fiber receiving area that includes a drum for receiving the length ofoptical fiber. The fiber receiving area includes a fiber connector area,for receiving the first end and for presenting the first end forconnection to a light source or light sensor, and a module connectionarea, for receiving the second end and for presenting the second end forautomatic connection to the electronic module.

[0011] The present invention is further directed to a cassette thatfacilitates automatic assembly of an electro-optical device thatincludes at least one length of optical fiber (having a first end and asecond end) and an electronic module. The cassette includes anelectronic module receiving area that receives the electronic module anda spool receiving area that receives at least one spool for carrying thelength of optical fiber. The at least one spool includes a fiberconnector area, for receiving the first end and for presenting the firstend for connection to a light source or light sensor, and a moduleconnection area, for receiving the second end and for presenting thesecond end for automatic connection to the electronic module.

[0012] The present invention is also directed to a method forautomatically assembling a spool that transports of a length of opticalfiber that has a first end and a second end. The spool includes a drumand a spool base, wherein the spool base includes at least two fiber endareas for retaining the first end and the second end. The methodincludes retaining the first end in one of the fiber end areas; windingthe length of optical fiber around the drum; and retaining the secondend in a second of the fiber end areas.

[0013] The present invention is also directed to a method forautomatically assembling a spool that transports of a length of opticalfiber having a first end and a second end. The spool includes a drum anda spool base. The spool base includes a fiber connector area, whichincludes a connector clip, and a module connection area, which includesa fiber end latch. The method includes inserting the first end into theconnector clip; winding the length of optical fiber around the drum; andinserting the second end into the fiber end latch.

BRIEF DESCRIPTION OF FIGURES

[0014] The accompanying drawings, wherein like reference numerals areemployed to designate the same or similar parts or steps, are includedto provide a further understanding of the invention, are incorporated inand constitute a part of this specification, and illustrate embodimentsof the invention that, together with the description, serve to explainthe principles of the invention:

[0015]FIG. 1 shows a preferred embodiment of a spool assembly inaccordance with the present invention.

[0016]FIG. 2 is an isometric, partially exploded view of a spoolassembly in accordance with a preferred embodiment of the presentinvention.

[0017]FIG. 3 is an isometric view of a preferred embodiment of a spoolassembly in accordance with the present invention.

[0018]FIG. 4 is an isometric, exploded view of a preferred embodiment ofa spool assembly in accordance with the present invention.

[0019]FIG. 5 is an isometric view of a preferred embodiment of a spoolassembly in accordance with the present invention.

[0020]FIG. 6 is an isometric view of a preferred embodiment of a spoolassembly in accordance with the present invention.

[0021]FIG. 7 is an isometric view of a preferred embodiment of atwo-spool assembly with one spool assembly partially exposed, inaccordance with the present invention.

[0022]FIG. 8 is an isometric, exploded view of a preferred embodiment ofa cassette assembly in accordance with the present invention.

[0023]FIG. 9 is an isometric, exploded view of a preferred embodiment ofa cassette assembly in accordance with the present invention.

[0024]FIG. 10 is an isometric view of a preferred embodiment of acassette assembly in accordance with the present invention.

[0025]FIG. 11 is an isometric, exploded view of a preferred embodimentof a cassette assembly in accordance with the present invention.

[0026]FIG. 12 is an isometric view of a preferred embodiment of acassette assembly in accordance with the present invention.

[0027]FIG. 13 is a view of a preferred embodiment of a cassette assemblyin accordance with the present invention.

[0028]FIG. 14A is an isometric view of a preferred embodiment of acassette assembly in accordance with the present invention.

[0029]FIG. 14B is an isometric view of a preferred embodiment of acassette assembly in accordance with the present invention.

[0030]FIG. 15 is an isometric view of a preferred embodiment of acassette assembly in accordance with the present invention.

[0031]FIGS. 16A and 16B are flow charts illustrating a method forautomatically assembling an electro-optical device in accordance with apreferred embodiment of the present invention.

[0032]FIGS. 17A, 17B and 17C are flow charts illustrating a method forautomatically assembling an electro-optical device in accordance with apreferred embodiment of the present invention.

[0033]FIG. 18 is a flow chart illustrating a method for assembling aspool in accordance with a preferred embodiment of the presentinvention.

DETAILED DESCRIPTION

[0034] Reference will now be made in detail to the preferred embodimentsof the present invention, examples of which are illustrated in theaccompanying drawings. It is to be understood that the Figures anddescriptions of the present invention included herein illustrate anddescribe elements that are of particular relevance to the presentinvention while eliminating, for purposes of clarity, other elements.

[0035] In one aspect of the present invention, a spool facilitatesautomatic handling of one or more lengths of optical fiber and can beused for storing, shipping, and further processing of the opticalfibers, including facilitating manipulation of the optical fibers byautomatic assembly equipment. With reference to FIG. 1, a spool assembly(1) is shown, which captures a length of optical fiber (2). Spoolassembly (1) includes a drum (3) that receives the length of opticalfiber (2). The length of optical fiber (2) has a first end (4) and asecond end (5). Spool assembly (1) also includes a spool base (6),coupled to the drum (3). Spool base (6) includes at least two fiber endareas, fiber end area (7) and fiber end area (8), which retain the firstend (4) and the second end (5) and prevent the length of optical fiber(2) from unspooling. At least a portion of fiber end area (7) and/orfiber end area (8) can be formed as inserts to accommodate variousdifferent types of fiber end configurations. Spool assembly (1) is sizedand configure such that it is capable of being used in connection withautomatic assembly equipment.

[0036] The general configuration of the spool described with referenceto FIG. 1 can be used to accommodate many different types of assemblies.For example, this general configuration may accommodate an optical fiberwith a connector or electronic element (such as a laser, lamp, diode, orsensor) on one end while leaving the other end bare. Alternatively, thespool may be configured to accommodate an optical fiber withconnectors/electronic elements on each of its ends or, conversely, anoptical fiber with two bare ends. Thus, the spool may be configured toaccommodate fibers that are already connected to electronic elements;fibers that are connected to other fibers by splicing; or fibers thatsimply must be prevented from tangling in subsequent operations orduring use. These accommodations may be easily achieved by changing theconfiguration of fiber end area (7) and/or fiber end area (8). Formingat least a portion of fiber end area (7) and/or fiber end area (8) asinserts is particularly advantageous in this regard.

[0037] The following describes some specific preferred embodiments ofthe invention. As shown in FIG. 2, spool assembly (101) comprises a drum(120) and a spool base (150). The drum (120), which is used forreceiving optical fibers, is coupled to the spool base (150) along thedrum central axis (122) and the spool base central axis (152). The drum(120) and the spool base (150) can be formed as two separate units or,as shown in FIG. 3, as a single integrated unit. When made as separateunits, as shown in FIG. 2, a drum molding (151) is used for coupling thedrum (120) to the spool base (150). Drums, such as drum (120), can beconstructed in different sizes to accommodate optical fibers ofdifferent lengths and diameters and coupled to the spool base (150)using the drum molding (151). In addition, this design allows for thesubstitution of different types of spool bases and corresponding fiberend entrapments, as discussed in more detail with reference to FIGS. 3and 4.

[0038] As shown in FIG. 3, the spool assembly (102) includes a length ofoptical fiber (10). The drum (120) has flanges (121) to maintain thelength of optical fiber (10) securely on the drum (120). In anotherembodiment, shown in FIG. 4, the drum (123) has a concave surface (125)on its outer diameter that retains the length of optical fiber. One endof the length of optical fiber (10) is held by a connector (15). Thelength of optical fiber (10) is wound around the drum (120) and theconnector (15) is inserted in the connector clip (131) and held byconnector locks (132). The connector clip (131) may be integral with thespool base (150) or may be formed as an insert, which allows for the useof different connector end configurations by inserting the particularconnector clip that matches the desired connector end configuration. Thespool assembly of the present invention, therefore, is versatile andenables accommodation of different pigtail terminations. The connector(15) is presented in fiber connector area (130) in a manner that allowsfor connection of connector (15) to a light sensor (if the electricalunit to which the fiber is to be connected is a transmitter) or a lightsource (if the electrical unit to which the fiber is to be connected isa receiver). Connector (15) may be connected to the light source/sensorby automatic assembly equipment. Alternatively, in some embodiments,connector (15) may be precisely positioned in fiber connector area (130)such that connection to a light source/sensor can be made without needfor automatic assembly equipment.

[0039] As shown in FIG. 4, in module connection area (140) of the spoolassembly (103), the assembly end (12) of the optical fiber (10) can beasserted into the fiber end latch (141). In particular, the bend limiter(13) on the assembly end (12) may be held in the fiber end latch (141)such that ferrule (14) is available for gripping by an assembly machineprior to its release from the latch (141) during optical assembly.Exerting pressure on tab (143) allows for release of the assembly end(12) from the latch (141). Upon its release, fiber end (16) can be, ifrequired, automatically connected to an electronic module by an assemblymachine. When maintained in the fiber end latch (141), the fiber end(16) is protected by the fiber end cover (142). The fiber end latch(141) may be constructed as an insert, which allows for the use ofdifferent end terminations by inserting the particular fiber end latchthat matches the desired end termination.

[0040] In accordance with the present invention, the spool assembly,such as that shown in FIG. 4, facilitates bonding of the optical fiberend to an electronic module (although, as stated previously, theinvention covers spool systems that do not include electronic elements).For example, as shown in FIG. 4, the optical bench adapter (145) may beused to facilitate epoxy bonding during electro-optical assembly. Thefiber end (16) held in the fiber end latch (141) may be released uponexerting pressure on the tab (143) of the fiber end latch (141). Uponrelease, as shown in FIG. 5, fiber end (16) may be inserted into opticalbench (146), which is held in optical bench adapter (145). The opticalbench adapter (145) may be constructed as an insert, which allows forthe use of different bonding methods by inserting the desired opticalbench adapter (145) into module connection area (140).

[0041]FIG. 6 depicts an alternate embodiment of the spool assembly ofthe present invention that provides for a different arrangement ofmodule connection area (140), thereby facilitating a second type ofoptical fiber bonding. Module connection area (140) of spool assembly(104) is designed to facilitate assembly by laser welding. Electronicunit (148) is typically held by assembly equipment in a fixtureappropriate for laser welding. The assembly end (12) held in the fiberend latch (141) is released upon exerting pressure on the tab (143).Automatic assembly equipment then properly positions fiber end (16) (notshown) with respect to the fixtured electronic unit (148), perform theweld, and removes the electronic unit (148) from the fixture with thefiber attached. The assembly equipment then deactivates latch (147) andinserts the electronic module (148) with the fiber end (16) attachedinto module adapter (149). Once the electronic module (148) and theattached fiber are in place, the latch (147) is activated, securelyholding them in place. As shown in the FIG. 6, latch (147) may also beconstructed as an insert, thereby providing for additional versatility.

[0042] The ability to form different portions of the spool assemblies ofthe present invention as inserts results in great versatility andenables accommodation of different connections and/or bonding methods.

[0043] Two or more spools can be coupled together for use in handling ortransporting optical fibers and assembling such optical fibers intooptical assemblies (such as, for example, modulators, comb filters,multiplexers, frequency multipliers, amplifiers and other similaroptical systems), in accordance with the present invention. As shown inFIG. 7, two spools (106A & 106B) are coupled to each other along thecentral axes (119A & 119B) of their respective drums (190A & 190B). Eachconnector (15A & 15B) is inserted into its respective connector clip(131A & 131B), thereby positioned for automatic connection to assemblyequipment, if necessary. Each ferrule (14A & 14B) is positioned forautomatic pickup by assembly equipment.

[0044] Once an optical fiber has been captured on a spool, the spool canbe used to store the optical fiber and to ship the optical fiber, forexample, from a vendor to an assembly facility where the optical fiberwill be automatically integrated into an optical assembly. In addition,the spool serves to maintain and align the fiber during testingoperations at which time light is propagated through the fibers, withoutmanual manipulation.

[0045] A multiple-spool assembly, such as that shown in FIG. 7, or asingle spool assembly, such as those shown in FIGS. 1-6, can be insertedinto a cassette, as described more fully with reference to FIGS. 8-10,14B, 14A and 15. As shown in FIG. 8 illustrating cassette assembly(201), a cassette (200) is designed to capture and retain an electronicmodule (221) and, in the illustrated embodiment, two spools (107A &107B). The cassette (200) facilitates assembly and transportation ofoptical assemblies (comprising, in this illustration, two optical fibers(10A & 10B) and an electronic module (221)). Thus, the cassette assembly(201) performs double duty as a fixture for retaining the electronicmodule (221), bonding fiber ends (16A and 16B) to electronic module(221), and presenting the fiber connectors (15A & 15B) for connection toa light source/sensor, as well as a protective device for shipment offinished assemblies.

[0046] With reference to FIG. 9, illustrating an exploded view of acassette assembly (202), cassette (200) comprises a spool receiving area(250) for receiving one or more spools (108A & 108B). The spools (108A &108B) may be retained securely in the spool receiving area (250) byspool latches (251). The fiber connector (15B) may be inserted into theconnector clip (131B) and the fiber end (16B) of the assembly end (12B)may be inserted into the fiber end latch (141B). The connector clip(131B) and the fiber end latch (141B) may be inserted in the spool(108B) at connector clip insert (1310 B) and fiber end latch insert(1410B), respectively. Furthermore, the optical bench adapter (145B) maybe inserted in the spool (108B) at optical bench adapter insert (1450B).Similarly, fiber connector (15A) may be inserted into the connector clip(131A) and the fiber end (16A) of the assembly end (12A) may be insertedinto the fiber end latch (141A). The connector clip (131A) and the fiberend latch (141A) may be inserted in the spool (108A) at connector clipinsert (1310A) and fiber end latch insert (1410A), respectively. Theoptical bench adapter (145A) may be inserted in the spool (108A) atoptical bench adapter insert (1450A). Typically, optical bench (146) isobtained from a storage device by automatic assembly equipment andplaced into a fixture. Assembly end (12A) is taken from fiber end latch(141A) by the assembly equipment, aligned to the fixtured optical bench(146), and epoxied. The completed assembly comprising the optical bench(146) and the fiber is then placed into the optical bench adapter(145A). In alternate embodiments, however, the optical bench (146)remains in the cassette (200) while being epoxied to the assembly end(12A).

[0047] As shown further in FIG. 9, the height (designated by “h”) of thecassette (200) may be designed to accommodate any given number of spools(in this embodiment, two spools (108A & 108B)) consistent with thenumber of optical fibers desired in the cassette assembly (202). Thespool assembly hole (252) (also shown in FIG. 10) provides access tofiber connectors (1 5A & 15B) by automatic assembly equipment, ifrequired. With further reference to FIG. 9, the cassette (200) furthercomprises an electronic module receiving area (220) for receiving anelectronic module (221). The electronic module (221) is retainedsecurely by module latches (223). The design of module latches (223) maybe variable depending on the physical design of electronic module (221).The module assembly hole (225) located in the electronic modulereceiving area (220) provides access to the electronic module (221) byassembly equipment. The positioning of the electronic module (221) inelectronic module receiving area (220) facilitates automatic connectionof the fiber ends (16A & 16B) of the optical fibers (10A & 100B),respectively, to the electronic module (221). Once the spools (108A &108B) and the electronic module (221) are properly loaded in thecassette (200), the cassette assembly (202) can be used to ship theelectro-optical device and/or for further processing of opticalassemblies.

[0048]FIG. 10 shows a two-spool assembly that has been inserted into acassette and has had the ends of its optical fibers secured to anelectronic module, as described with reference to FIG. 9.

[0049] In another preferred embodiment of the present invention, asshown in FIGS. 11, 12, and 13, a cassette (210) receives the lengths ofoptical fiber (10A & 10B) directly, without use of the separate spool(s)described herein. In the cassette assembly (207) of FIG. 14, thecassette (210) and spool drum (257) are a single, integral unit. Thecassette (210) comprises an electronic module receiving area (270) forreceiving an electronic module (221). The electronic module (221) may beinserted in the electronic module receiving area (270) and retained byelectronic module latches (271), shown in FIG. 12. With reference toFIG. 11, the cassette (210) also comprises a fiber receiving area (260)on the underside of cassette (210), that receives the lengths of opticalfiber (10A & 10B).

[0050] Spool drum (257) includes one or more stepped concentric ringsaround which individual fibers may be wound. As shown in FIG. 13, whichshows the underside of cassette (210) spool drum (257) includes twostepped rings (257A & 257B) for receiving optical fibers (10A & 10B).Molded cuts in the rings allow the fibers from inner rings to pass tothe exterior of the largest ring. Molded depressions in the floor of thecassette (210) allow the fibers from the inner ring (257A) to pass underfibers wound the larger diameter ring (257B). To ensure that the opticalfibers (10A & 10B) do not commingle and/or entangle, a retainer (253) issnapped onto cassette (210) over spool drum (257). Retainer (235)includes cutouts (295) to preclude crimping of the optical fibers asthey cross over fibers wound on larger rings. To eliminate stress on thefiber that may occur during manipulation during assembly, the cassette(210) includes draw areas (300A & 300B), which allow for some excessfiber to be loosely held between fiber end latches (256A & 256B) andfiber holder (260).

[0051] As shown in FIGS. 11 and 12, the fiber connectors (15A & 15B),into which one end of each length of optical fiber (10A & 10B) has beeninserted, may be inserted into connector channels (254A & 254B),respectively. The assembly ends (12A & 12B) may be inserted into fiberend latches (256A & 256B) and inserted into fiber end latch receivingareas (259A & 259B). An electronic module cap (258) may be coupled tothe cassette (210) such that it covers all or part of electronic module(221). The electronic module cap (258) may include a hole (262) to allowfor protrusion of power connector (261) of electronic module (221). Thisdesign facilitates connection of the electronic module (221) to a powersupply.

[0052] As shown in FIG. 12, the placement of the connector channels(254A & 254B) facilitates automatic connection of the fiber connectors(15A & 15B) to assembly equipment, if required. Further, the placementof the electronic module (221) in relative location to fiber end latchreceiving areas (259A & 259B), into which fiber end latches (256A &256B) have been inserted, facilitates automatic connection of theassembly ends (12A & 12B) to the electronic module (221).

[0053] Thus, the system shown in FIGS. 11, 12 and 13 facilitatesshipment of fibers to a manufacturing area, retaining an electronicmodule while presenting the fibers for assembly, and protecting thefinished assemblies during storage and shipment.

[0054] The specific preferred embodiments described herein, and all ofthose embodiments that fall within the scope of the present invention,may be used to facilitate automatic assembly of optical devices. Inparticular, an optical fiber may be captured on a spool of the presentinvention, as described with reference to FIGS. 1-7, by automaticassembly equipment. Then, an electronic module and a desired number ofspools may be loaded into a cassette by automatic assembly equipment.For example, with reference to FIG. 14A, an electronic module (221),covered by electronic module cover (224), and two spools (111A & 111B)have been loaded into cassette (200) to form the cassette assembly(205). The assembly equipment may, if required, automatically connect tothe connectors (15A & 15B) retained in the connector clips (131A & 131B)through the spool assembly hole (252) (also shown in FIG. 10) in thecassette (200). Alternatively, connectors (15A & 15B) are preciselypositioned in cassette (200) such that connection to a lightsource/sensor can be made without use of assembly equipment.

[0055] As further shown in FIG. 14A, the placement of the electronicmodule (221) and the spools (111A & 111B) in cassette (200) allowsautomatic assembly equipment to grip the optical fibers (hidden here),by releasing ferrules (14A & 14B) from the fiber end latches (141A &141B) (as shown in FIG. 9) by having the automatic assembly equipmentexert pressure on their respective tabs (143A & 143B), and to positionthe fiber ends (16A & 16B) (as shown in FIG. 8) towards the electronicmodule (221) for assembly. The tab (143A) of the spool (111A) can beaccessed through the tab access hole (231) in the underside of thecassette (200), as shown in FIG. 9. The tab (143B) of spool (111B) canbe accessed through a tab access notch (153B) of spool (111A), as shownin FIG. 14A. An alternative embodiment of a cassette assembly (206), asshown in FIG. 15, allows direct access to the fiber end latch (141B) ofthe spool (112B), thereby eliminating any need for a tab access notch.FIG. 14B shows cassette assembly (301) and includes electronic module(302) without a cover. Thus, bonding area (303) of electronic module(302) is open and allows for an assembly machine to grip the ferrules(304A & 304B) upon their release, move them to the bonding area (303),and bond the fiber ends (not shown) to the electronic module (302).Thus, both FIGS. 14B and 15 show embodiments in which fiber ends havebeen bonded to electronic module (221). In alternative embodiments, theelectronic module (221) is held in a fixture, outside the cassette,during the bonding process and placed back into cassette by automaticassembly equipment upon completion.

[0056] As shown in FIG. 15, the design of the electronic modulereceiving area (220) allows further processing as desired while securelyretaining both the electronic module (221) and the spools (112A & 112B).The design also allows access to the internals of the electronic module(221) either from above or from beneath the electronic module (221),through the module assembly hole (225), shown in FIG. 9. In someembodiments, an electronic module cover (224), as shown in FIG. 15, isused to cover electronic module (221). As also shown in FIG. 15, a powersource can be connected to electronic module (221) by automatic assemblyequipment via power connector (310). While these assembly steps aredescribed above as being performed automatically by assembly equipment,one or more of these steps may be performed manually.

[0057] A cassette assembly of the present invention can be used infurther handling and processing of the optical fibers and the electronicmodule without need for any additional packaging or carriers.Furthermore, the cassette assembly may serve as a shipping container.The cassette assembly may be inserted into packaging material or wrappedin shrink material for transporting to the end user who may, in order touse the fibers and electronic module in an optical assembly, remove theelectronic module (221) from the cassette (200), remove the spools (109A& 109B), unclip the fiber connectors (15A & 15B) and remove the opticalfibers from the spools (109A & 109B) as shown, for example, in FIG. 10.

[0058] Methods for carrying out the objects of the present invention aredescribed with reference to FIGS. 16A, 16B, 17A, 17B, 17C and 18. Withreference to FIGS. 16A and 16B, a preferred embodiment of a method forautomatically assembling an electro-optical device is illustrated. Theelectro-optical device includes a cassette, one or more spools, and anelectronic module. In step 1601, one or more spools are loaded into aspool receiving area of the cassette. The spools each capture a lengthof optical fiber, which includes a first end and a second end. In step1602, the electronic module is loaded into an electronic modulereceiving area of the cassette. In step 1603, the cassette is loadedinto assembly equipment. In step 1604, the first end of the fiber ismaintained for connection to a light source/sensor, with or without useof automatic assembly equipment. In step 1605, the first end of thefiber is connected to a light source/sensor and the electronic module isconnected to a power supply, if required. In step 1606, the second endof the fiber is connected to the electronic module by automatic assemblyequipment. In some embodiments, this step is performed while theelectronic module is not retained in the cassette (i.e., either beforeit is loaded into the cassette or it is removed from the cassette forthe connection procedure). In the preferred embodiment, connecting thesecond end of the fiber to the electronic module is accomplished by,first, bonding the second end of the fiber to an electronic unit (usinga very accurate and precise connection) and, then, bonding theelectronic unit to the electronic module. In alternate embodiments, theelectronic unit is bonded to the electronic module and, then, the secondend of the fiber is bonded to the electronic unit. In step 1607, it isdetermined whether the assembly includes additional fibers/electronicunits to be bonded to the electronic module. If so, it is determined instep 1610 whether the fist ends are maintained separately. If so, theprocess repeats from step 1604 and, if not, the process repeats fromstep 1606. If it is determined that the assembly does not includeadditional fibers/electronic units to be bonded to the electronicmodule, in step 1608, any electronic and optical connections aredetached and, in step 1609, the cassette is removed from the assemblyequipment.

[0059] With reference to FIG. 17A, a preferred embodiment of a methodfor automatically assembling an electro-optical device is illustrated.The electro-optical device includes a cassette, one or more lengths ofoptical fiber, and an electronic module. In step 1701, the lengths ofoptical fiber (each including a first end and a second end) are loadedinto an optical fiber receiving area of the cassette and a cover isplaced over the area to retain the fiber. In step 1702, an electronicmodule is loaded into an electronic module receiving area of thecassette. In step 1703, the cassette is loaded into assembly equipment.In step 1704, the first end of the fiber is maintained for connection toa light source/sensor, with or without use of automatic assemblyequipment. In step 1705, the first end of the fiber is connected to alight source/sensor and the electronic module is connected to a powersupply, if required. In step 1706, the second end is picked up byassembly equipment and bonded to the electronic module. In oneembodiment the second end is positioned in the electronic module on theelectronic unit and bonded to the electronic unit installed in theelectronic module receiving area of the cassette. In step 1707, it isdetermined whether the assembly includes additional fiber ends to bebonded to the electronic module. If so, it is determined in step 1710whether the first ends are maintained separately. If so, the processrepeats from step 1704 or, if not, the process repeats from step 1706.If it is determined that the assembly does not include additional fiberends to be bonded to the electronic module, in step 1708, any electronicand optical connections are detached and, in step 1709, the cassette isremoved from the equipment.

[0060] In certain embodiments, the cassette further includes a drum, afiber connector area and a module connection area. In this embodiment,step 1701 includes, as shown in FIG. 17C, releasably securing the firstend in the fiber connector area in step 1710; winding the length ofoptical fiber around the drum in step 1720; and releasably securing thesecond end in the module connection area in step 1730. In otherembodiments, the lengths of optical fiber are pre-loaded into theoptical fiber receiving area of said cassette and step 1701 is notnecessary.

[0061] With reference to FIG. 18, a method for automatically assemblinga spool that transports of a length of optical fiber (including a firstend and a second end) is shown. The spool includes a drum and a spoolbase, which may be separate pieces or comprise a single unit. The spoolbase includes at least two fiber end areas. In some embodiments, onefiber end area is a fiber connector area (which includes a connectorclip) and a second fiber end area is a module connection area (whichincludes a fiber end latch). In step 1801 of the method, the first endof the fiber is maintained in one fiber end area (for example, isinserted into the connector clip). In step 1802, the length of opticalfiber is wound around the drum by automatic assembly equipment. In step1803, the second end is maintained in a second fiber end area (forexample, is inserted into the fiber end latch).

[0062] While the invention has been described in detail and withreference to specific embodiments thereof, it will be apparent to oneskilled in the art that various changes and modifications can be madetherein without departing from the spirit and scope thereof. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A spool assembly used in connection withautomatic assembly equipment for capturing a length of optical fibercomprising: a drum for receiving said length of optical fiber, saidlength of optical fiber comprising a first end and a second end; and aspool base, coupled to said drum, comprising at least two fiber endareas for retaining said first end and said second end.
 2. A spoolassembly used in connection with automatic assembly equipment forcapturing a length of optical fiber comprising: a drum for receivingsaid length of optical fiber, said length of optical fiber comprising afirst end and a second end; and a spool base, coupled to said drum,comprising: a fiber connector area for retaining said first end andpresenting said first end for connection to a light source or lightsensor; and a module connection area for retaining said second end andpresenting said second end for automatic connection to an electronicmodule.
 3. The spool of claim 1 or 2 wherein said drum and said spoolbase comprise a single unit.
 4. The spool of claim 1 or 2 wherein saiddrum comprises a central axis and wherein a plurality of said spools arecoupled along said central axis.
 5. The spool of claim 2 wherein atleast a portion of said fiber connector area is formed as an insert forcoupling to said spool base.
 6. The spool of claim 2 wherein said fiberconnector area comprises a connector clip for capturing said first end.7. The spool of claim 2 wherein at least a portion of said moduleconnection area is formed as an insert for coupling to said spool base.8. The spool of claim 2 wherein said module connection area comprises afiber end cover.
 9. The spool of claim 2 wherein said module connectionarea comprises a fiber end latch for capturing said second end.
 10. Thespool of claim 9 wherein, upon deactivating said fiber end latch, saidsecond end is released for attachment to said electronic module.
 11. Thespool of claim 1 or 2 wherein said spool is configured to facilitateautomatic alignment of said length of optical fiber.
 12. The spool ofclaim 1 or 2 wherein said spool facilitates transportation of saidlength of optical fiber.
 13. The spool of claim 1 or 2 wherein saidspool facilitates manipulation of said length of optical fiber byautomatic assembly equipment.
 14. The spool of claim 1 or 2 wherein saidspool facilitates storage of said length of optical fiber.
 15. The spoolof claim 1 wherein at least a portion of at least one of said fiber endareas are formed as inserts for coupling to said spool base.
 16. Acassette that facilitates automatic assembly of an electro-opticaldevice, wherein said device comprises at least one length of opticalfiber and an electronic module, comprising: an electronic modulereceiving area that receives said electronic module; and a fiberreceiving area comprising a drum for receiving said at least one lengthof optical fiber, said length of optical fiber having a first end and asecond end; wherein said fiber receiving area comprises a fiberconnector area for receiving said first end and for presenting saidfirst end for connection to a light source or light sensor and a moduleconnection area for receiving said second end and for presenting saidsecond end for automatic connection to said electronic module.
 17. Acassette that facilitates automatic assembly of an electro-opticaldevice, wherein said device comprises at least one length of opticalfiber and an electronic module, comprising: an electronic modulereceiving area that receives said electronic module; and a spoolreceiving area that receives at least one spool for carrying said lengthof optical fiber, said length of optical fiber having a first end and asecond end; wherein said at least one spool comprises a fiber connectorarea for receiving said first end and for presenting said first end forconnection to a light source or light sensor and a module connectionarea for receiving said second end and for presenting said second endfor automatic connection to said electronic module.
 18. The cassette ofclaim 17 wherein said electronic module receiving area facilitatesautomatic connection of said electronic module to an electrical powersource.
 19. The cassette of claim 17 wherein said electronic modulereceiving area comprises an electronic module cover for securing saidelectronic module.
 20. The cassette of claim 17 wherein said fiberconnector area is configured to facilitate automatic alignment of saidlength of optical fiber.
 21. The cassette of claim 20 wherein saidautomatic alignment facilitates testing of said length of optical fiber.22. The cassette of claim 17 wherein said cassette facilitates storageof said electro-optical device.
 23. The cassette of claim 17 whereinsaid cassette facilitates shipping of said electro-optical device.
 24. Amethod for automatically assembling a spool that transports of a lengthof optical fiber, said length of optical fiber having a first end and asecond end, wherein said spool comprises a drum and a spool base,wherein said spool base comprises at least two fiber end areas forretaining said first end and said second end, said method comprising thesteps of: (A) retaining said first end in one of said fiber end areas;(B) winding said length of optical fiber around said drum; and (C)retaining said second end in a second of said fiber end areas.
 25. Amethod for automatically assembling a spool that transports of a lengthof optical fiber, said length of optical fiber having a first end and asecond end, wherein said spool comprises a drum and a spool base,wherein said spool base comprises a fiber connector area, wherein saidfiber connector area comprises a connector clip, and a module connectionarea, wherein said module connection area comprises a fiber end latch,said method comprising the steps of: (A) inserting said first end intosaid connector clip; (B) winding said length of optical fiber aroundsaid drum; and (C) inserting said second end in said fiber end latch.